Book/Report

FZJ-2019-00461

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Bestimmung effektiver Massen von $^{3}$He-Quasiteilchen in verdünnten $^{3}$He/$^{4}$He-Mischungen mittels Tiefsttemperaturkalorimetrie

Simons, R. (Corresponding author)FZJ*

1995
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/21286

Report No.: Juel-3033

Abstract: Dilute solutions of $^{3}$He in superfluid $^{4}$He have been investigated by accurate measurements of the specific heat capacity C$_{v}$ for the following parameters: Temperature: 20 mK < T < 200 mK $^{3}$He-concentration: 1.3% < x$_{3}$ < 9.5 % Pressure: 0 bar, 10 bar and 20 bar The data could be fitted to an expression which describes the specific heat capacity of an ideal Fermi gas, yielding the Fermi temperature T$_{f}$, the precise $^{3}$He-concentration in the cell and the effective mass m* of the $^{3}$He-quasiparticles. The main results are: $\bullet$ The dependence of T$_{f}$ (in mK) on the pressure p (in bar) and the $^{3}$He-concentration x$_{3}$ (in %) can be described by the formula: T$_{f}$ = (125.2 - 0.53 $\cdot$ p) $\cdot$ $x^{0.64}_{3}$ $\bullet$ At constant pressure the effective mass m* of the $^{3}$He-quasiparticles increases with $^{3}$He-concentration: $\left( \frac{\partial m*(x_{3},p)}{\partial x_{3}} \right)_{p}$ > 0 The knowledge of m* is valuable for other experiments on $^{3}$He/$^{4}$He-mixtures, because the density of states of the quasiparticles at the Fermi level can be evaluated directly from m*. Moreover the results of this work should give a basis for an improved estimate of the critical temperature for the superfiuid transition of the $^{3}$He-component in these dilute solutions.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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